ANDROID: mmc: move to a SCHED_FIFO thread

(cherry picked from commit 011e507b413393eab8279dac8b778ad9b6e9971b)

Running mmcqd as a prio 120 thread forces it to compete with standard
user processes for IO performance, especially when the system is under
severe CPU load. Move it to a SCHED_FIFO thread to reduce the impact of
load on IO performance.

Signed-off-by: Tim Murray <timmurray@google.com>
Bug: 25392275
Change-Id: I1edfe73baa25e181367c30c1f40fee886e92b60d

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 6f4323c6d6536c8855ca2a8bef8f8087bb5d252e..6a4cd2bb4629c4b945cf096574a9813a685a7d3a 100644 (file)
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -19,6 +19,7 @@
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
+#include <linux/sched/rt.h>
 #include "queue.h"
 
 #define MMC_QUEUE_BOUNCESZ     65536
@@ -50,6 +51,11 @@ static int mmc_queue_thread(void *d)
 {
        struct mmc_queue *mq = d;
        struct request_queue *q = mq->queue;
+       struct sched_param scheduler_params = {0};
+
+       scheduler_params.sched_priority = 1;
+
+       sched_setscheduler(current, SCHED_FIFO, &scheduler_params);
 
        current->flags |= PF_MEMALLOC;